553 research outputs found
Avaliação da fertilidade dos solos do Distrito Federal.
O SNLCS tem procurado ampliar o alcance e a utilização prática, dos dados obtidos através dos levantamentos de solos que realiza. Prosseguindo as pesquisas que objetivam a elaboração do mapa de solos do Brasil a nível de reconhecimento, esta entidade vem complementando seus trabalhos com mapas de aptidão agrícola das terras, em relação com diferentes tipos de manejo e culturas. Dentro dos parâmetros usados para definir a aptidão agrícola dos solos, a fertilidade e o mais facilmente controlável e aquele cuja alteração modifica mais sensivelmente a produtividade das terras. Por outro lado, os mapas de aptidão, pela sua natureza, não mostram claramente as limitações de uso devido unicamente ao nível de fertilidade das terras. Tal informação é de grande importância ao estudo de viabilidade econômica de projetos agropecuários, por permitir estimar a necessidade de fertilizantes e corretivos para determinada área. A análise conjunta dos mapas de classificação e aptidão agrícola e ainda de uma avaliação da fertilidade dos solos, daria aos usuários dos trabalhos de levantamento uma visão mais completa dos recursos disponíveis, facilitando as decisões quanto ao tipo de exploração agrícola e ao sistema de manejo mais adequado em cada caso. O presente projeto propõe a complementação de cada trabalho de levantamento com uma avaliação e quantificação da fertilidade, cuja precisão e confiabilidade serão tanto maiores quanto maior for o nível de detalhe do levantamento de solos em que seja baseado.bitstream/item/62835/1/CNPS-BOL.-TEC.-74-80.pdf; bitstream/item/125962/1/Avaliacao-da-Fertilidade-dos-Solos-do-Distrito-Federal.pdfAcompanha 1 mapa, color. Escala 1:100.000
Atmospheric pressure non-equilibriumplasma for the production of composite materials
In the evolving field of tissue engineering, continuous advances are required
to improve scaffold design and fabrication to obtain biomimetic supports for
cell adhesion, proliferation, penetration and differentiation. Both electrospun
fibrous scaffolds and hydrogels are used in this field since they well
reproduce the structure of the extracellular matrix (ECM) of many biological
tissues. Limitations of these two types of materials can be overcome
through their combination, by developing composite structures combining
enhanced mechanical properties (provided by the fibrous components) and
improved cell penetration (provided by the gel phase) in a superior ability to
mimic natural ECM that is constituted by both a fibrous protein network and
a hydrogel matrix. Here we develop new composite materials made of
electrospun PLLA scaffolds and poly(amidoamine) hydrogels with different
degrees of crosslinking. To promote compatibilization and good adhesion
between the two materials, surface chemical reactions between hydrogels
and PLLA mats are induced by inserting amino functional groups on
electrospun PLLA mats by means of atmospheric pressure non-thermal
plasma. Results will be presented concerning the exposure of PLLA
substrates to the plasma region generated by a Dielectric Barrier Discharge
at atmospheric pressure, driven by a HV Amplifier connected to a function
generator operating with a microsecond rise time and operated in N2.
Surface and solid-state thermo-mechanical characterizations of plasma
treated substrates and of resulting composite materials at different
crosslinking degrees are presented. Results of mechanical tests show a high
adhesion between hydrogel and plasma treated PLLA electrospun mats,
underlining the opportunity to use atmospheric non-thermal plasmas to
fabricate a composite starting from two materials otherwise physically
incompatible. Potential effects of nanofibrous-hydrogel were evaluated by
investigating pluripotent stem cells response
The cusp effect in eta' --> eta pi pi decays
Strong final-state interactions create a pronounced cusp in eta' --> eta pi0
pi0 decays. We adapt and generalize the non-relativistic effective field theory
framework developed for the extraction of pi pi scattering lengths from K --> 3
pi decays to this case. The cusp effect is predicted to have an effect of more
than 8% on the decay spectrum below the pi+ pi- threshold.Comment: 11 pages, 8 figures; comment added, typos corrected, version
published in Eur. Phys. J.
A petro-chemical study of ancient mortars from the archaeological site of Kyme (Turkey)
Fourteen samples of ancient mortars (joint mortars and plasters) from the archaeological
site of Kyme (Turkey) were studied by optical microscopy (OM), X-ray fluorescence (XRF),
X-ray powder diffraction (XRPD), scanning electron microscopy (SEM-EDS) and micro-
Raman spectroscopy to obtain information about their composition.The study allowed us to
identify a new type of plaster inside the archaeological site of Kyme, not detected by previous
studies of this site, in which vegetable fibers were intentionally added to the mixture. The
combination of a petrographic analysis on thin sections by polarized light microscopy
with a chemical analysis, has allowed us to highlight similarities and differences between
the mortars and to get information about the evolution of constructive techniques in the
archaeological area
Optimal Path Planning for Autonomous Spraying UAS framework in Precision Agriculture
This paper presents a novel guidance and control strategy for multirotor Unmanned Aerial Systems (UASs) which aims to provide an autonomous and safe mission in precision agriculture applications.
In the last few years, the research in this field has always improved thanks to the advent of new technologies and with the launch of the first smart farms. Precision aerial spraying of Plant Protection Products (PPP) in vineyards is the focus of this work, highlighting several advantages in terms of quality management, time and cost. In particular, we propose a combination of a Traveling Salesman Problem (TSP) solver with the well-know Theta* algorithm to investigate optimal UAS trajectories in order to visit a specific number of plants that require intervention. The final goal is to demonstrate the fulfillment of the evaluated trajectory with the on-board control system of the vehicle in provision for UAS field testing.
Finally, the planning strategy is applied to two case studies so as to present the feasibility of a more efficient autonomous UAS path planning
State of Art and Perspectives in Catalytic Ozonation for Removal of Organic Pollutants in Water: Influence of Process and Operational Parameters
The number of organic pollutants detected in water and wastewater is continuously increasing thus causing additional concerns about their impact on public and environmental health. Therefore, catalytic processes have gained interest as they can produce radicals able to degrade recalcitrant micropollutants. Specifically, catalytic ozonation has received considerable attention due to its ability to achieve advanced treatment performances at reduced ozone doses. This study surveys and summarizes the application of catalytic ozonation in water and wastewater treatment, paying attention to both homogeneous and heterogeneous catalysts. This review integrates bibliometric analysis using VOS viewer with systematic paper reviews, to obtain detailed summary tables where process and operational parameters relevant to catalytic ozonation are reported. New insights emerging from heterogeneous and homogenous catalytic ozonation applied to water and wastewater treatment for the removal of organic pollutants in water have emerged and are discussed in this paper. Finally, the activities of a variety of heterogeneous catalysts have been assessed using their chemicalphysical parameters such as point of zero charge (PZC), pKa, and pH, which can determine the effect of the catalysts (positive or negative) on catalytic ozonation processes
How the recent BABAR data for P to \gamma\gamma* affect the Standard Model predictions for the rare decays P to l+l-
Measuring the lepton anomalous magnetic moments and the rare decays
of light pseudoscalar mesons into lepton pairs , serve as
important tests of the Standard Model. To reduce the theoretical uncertainty in
the standard model predictions, the data on the charge and transition form
factors of the light pseudoscalar mesons play a significant role. Recently, new
data on the behavior of the transition form factors at
large momentum transfer were supplied by the BABAR collaboration. There are
several problems with the theoretical interpretation of these data: 1) An
unexpectedly slow decrease of the pion transition form factor at high momenta,
2) the qualitative difference in the behavior of the pion form factor and the
and form factors at high momenta, 3) the inconsistency of
the measured ratio of the and form factors with the
predicted one. We comment on the influence of the new BABAR data on the rare
decay branchings.Comment: 11 pages, 3 figure
Search for Nucleon Decays induced by GUT Magnetic Monopoles with the MACRO Experiment
The interaction of a Grand Unification Magnetic Monopole with a nucleon can
lead to a barion-number violating process in which the nucleon decays into a
lepton and one or more mesons (catalysis of nucleon decay). In this paper we
report an experimental study of the effects of a catalysis process in the MACRO
detector. Using a dedicated analysis we obtain new magnetic monopole (MM) flux
upper limits at the level of for
, based on the search for
catalysis events in the MACRO data. We also analyze the dependence of the MM
flux limit on the catalysis cross section.Comment: 12 pages, Latex, 10 figures and 2 Table
Toward Virtual Testing of Unmanned Aerial Spraying Systems Operating in Vineyards
In recent times, the objective of reducing the environmental impact of the agricultural industry has led to the mechanization of the sector. One of the consequences of this is the everyday increasing use of Unmanned Aerial Systems (UAS) for different tasks in agriculture, such as spraying operations, mapping, or diagnostics, among others. Aerial spraying presents an inherent problem associated with the drift of small droplets caused by their entrainment in vortical structures such as tip vortices produced at the tip of rotors and wings. This problem is aggravated by other dynamic physical phenomena associated with the actual spray operation, such as liquid sloshing in the tank, GPS inaccuracies, wind gusts, and autopilot corrections, among others. This work focuses on analyzing the impact of nozzle position and liquid sloshing on droplet deposition through numerical modeling. To achieve this, the paper presents a novel six degrees of freedom numerical model of a DJI Matrice 600 equipped with a spray system. The spray is modeled using Lagrangian particles and the liquid sloshing is modeled with an interface-capturing method known as Volume of Fluid (VOF) approach. The model is tested in a spraying operation at a constant velocity of 2 m/s in a virtual vineyard. The maneuver is achieved using a PID controller that drives the angular rates of the rotors. This spraying mission simulator was used to obtain insights into optimal nozzle selection and positioning by quantifying the amount of droplet deposition
New MACRO results on atmospheric neutrino oscillations
The final results of the MACRO experiment on atmospheric neutrino
oscillations are presented and discussed. The data concern different event
topologies with average neutrino energies of ~3 and ~50 GeV. Multiple Coulomb
Scattering of the high energy muons in absorbers was used to estimate the
neutrino energy of each event. The angular distributions, the L/E_nu
distribution, the particle ratios and the absolute fluxes all favour nu_mu -->
nu_tau oscillations with maximal mixing and Delta m^2 =0.0023 eV^2. A
discussion is made on the Monte Carlos used for the atmospheric neutrino flux.
Some results on neutrino astrophysics are also briefly discussed.Comment: Invited Paper at the NANP03 Int. Conf., Dubna, 200
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